Moving a stanky car into the garage filled with storage bins (all over in there!), food (the freezer), laundry facilities, cleaning supplies, access to the house where the smell could permeate every item surrounding it is NOT a "thinking move" it is a "hiding move." They put the car in the garage to hide it. They took the battery out to keep Casey from taking it, they say, but truly only a little bit of searching would have found it. You don't put a car battery anywhere but onto the floor or workbench so that the acid inside does not seep out onto whatever is underneath. The rain, therefore, was not the reason the Anthony's put the car into the garage. George drove home in the rain, true enough. But each time one catches oneself saying "man, I'd have done....." and the Anthony's have done something else, it isn't because they're too stupid to figure out what others would have done. It is because they are deliberately doing the opposite to keep a secret, whatever that secret might be. This time, it was the car. I don't believe they were ever going to say anything about the stench in that car. I believe they thought they'd get Casey and Caylee home and whatever Casey might have killed would have remained a mystery they would help cover up. Only, it became Caylee that was missing, added to that smell, multiplied a million times by Casey refusing to relieve her mother's panic by saying where she was.
And the walls came tumbling down.